7D Focus LOCK?

Does the 7D have a method to LOCK focus -- not just the auto focus "start" you get with either a half-push on of the shutter button or the "AF-ON" button. But a LOCK where the green focus light stays on.

I'm reading the Magic Lantern 7D book and on page 41 it says:

Since depressing the shutter release button halfway performs the same function as AF-ON, you might wonder when you would use AF-ON. Because the shutter release also starts the exposure evaluation, there may be instances when you want to lock focus differently than exposure. In this case, you would first frame the scene for focus and press AF-ON, then reframe for exposure and press STAR [AE LOCK] to lock exposure, and, lastly, press shutter to take the picture.

Well ... this isn't working for me. Pressing the AF-ON button gets focus and a green light light to confirm -- but not a steady one that indicates a LOCK. (Assuming that is possible.) Yes, AE LOCK works. But then the shutter button just starts the focus process again.